Sorting

Organizing data in a specific order efficiently.

What is Sorting?

Sorting is the process of arranging elements in a specific order, often ascending or descending. It’s a fundamental concept in computer science, making data easier to analyze and search. Common sorting algorithms include Bubble Sort, Quick Sort, Merge Sort, and more.

How the Algorithm Works

Sorting algorithms vary in how they function, but their goal is always to rearrange a collection of data into a specific order. Here’s a brief look at two common approaches:

1. Comparison-Based Sorting

  • Example: Quick Sort, Merge Sort
  • These algorithms compare elements to determine their order and use this comparison to rearrange them.

2. Non-Comparison-Based Sorting

  • Example: Counting Sort, Radix Sort
  • These algorithms use techniques like counting frequencies or bucket placement, bypassing direct comparisons.

Key Steps in Most Sorting Algorithms

  1. Divide and Conquer: Some algorithms, like Merge Sort, divide the data into smaller pieces and sort them individually.
  2. Comparison or Placement: Decide the position of each element by comparing it to others or placing it based on predefined rules.
  3. Combine: Merge sorted parts back together into a single ordered structure.

Sorting can be as simple as swapping adjacent elements or as complex as building a heap structure.

Time & Space Complexities

Here are complexities for common sorting algorithms:

AlgorithmBest CaseWorst CaseAverage CaseSpace Complexity
Bubble SortO(n)O(n²)O(n²)O(1)
Selection SortO(n²)O(n²)O(n²)O(1)
Insertion SortO(n)O(n²)O(n²)O(1)
Merge SortO(n log n)O(n log n)O(n log n)O(n)
Quick SortO(n log n)O(n²)O(n log n)O(log n)
Heap SortO(n log n)O(n log n)O(n log n)O(1)
Counting SortO(n + k)O(n + k)O(n + k)O(k)
Radix SortO(nk)O(nk)O(nk)O(n + k)
Bucket SortO(n + k)O(n²)O(n + k)O(n)

When to Use

Sorting algorithms are essential in various scenarios:

  • Preparing data for binary search.
  • Visualizing data in an ordered way.
  • Optimizing other algorithms that require sorted input.
  • Solving problems like finding the kth smallest/largest element.

Code Examples

def print_array(arr):
    print(" ".join(map(str, arr)))

# Example usage
arr = [5, 2, 9, 1, 5, 6]
arr.sort()  # Python's inbuilt Timsort
print("Sorted Array:", arr)

Problems to Solve

WIP

Resources